JPH06323404A - Power train lubricating device for electric automobile - Google Patents

Abstract

PURPOSE:To satisfactorily supply lubricating oil to each section of a power train while using a small oil pressure pump which consumes little electric power and lighten the power train. CONSTITUTION:The planet gears 42P and 44P of a speed reduction gear 16 comprising a pair of planet gear devices are integrated and rotatably supported by a common carrier pin 78, and the lubricating oil discharged from an oil pressure pump to an opening 72 is led to the carrier pin 78 through first lubricating passages 70, 74, and 76. The other sections of the speed reduction gear 16 and a differential device 18 are lubricated by the lubricating oil which gradually flows out from second lubricating oil passages 70, 84, 105, 104, and 106, which supply lubricating oil to the side of an electric motor positioned at the left, while flowing, and the lubricating oil supplied to the electric motor side returns to an oil pan 66 through a return oil passage 130 opened near the suction port 68 of the oil pressure pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powertrain for an electric vehicle, and more particularly to a powertrain structure and a lubricating device which can favorably supply lubricating oil to each part of the powertrain using a small hydraulic pump with low power consumption. Is.

[0002]

2. Description of the Related Art As a kind of power train for electric vehicles,
An electric motor, a speed reducer, and a differential device that are concentrically and serially arranged in a housing are provided, and one of left and right system power output from the differential device is used as an axial center of the electric motor and the speed reducer. There is a type in which a portion is transmitted to one drive wheel via an intermediate shaft that is inserted. Since such a power train is arranged in the width direction of the vehicle,
Compared with the case of arranging in the front-rear direction of the vehicle, it is convenient in securing a space for loading a large battery, an indoor space, and the like. Japanese Patent Application No. 4-26 filed previously by the applicant of the present application
The device described in No. 9594 is an example thereof, and FIG. 7 is a skeleton diagram thereof.

In FIG. 7, the power output from the motor shaft 202 of the electric motor 200 is decelerated by the speed reducer 204 and then distributed to the left and right drive systems by the differential device 206, and one power is a cylinder. Motor shaft 202
Through the intermediate shaft 208 and the constant velocity joint 210R which are arranged concentrically with the motor shaft 202 through the right drive wheel 21.
2R, and the other power is transmitted to the left drive wheel 212L via the constant velocity joint 210L and the like. The electric motor 200, the speed reducer 204, and the differential gear 206 are concentrically and serially arranged in a housing 214 composed of a plurality of members, and the housing 214 includes the electric motor 20.
No. 0 stator 216 is fixed, and the motor shaft 202 fixed to the rotor 218 is the bearing 2
It is rotatably supported via 20R and 220L. The speed reducer 204 includes the first planetary gear device 222 and the second planetary gear device 222.
The first planetary gear unit 222 includes the planetary gear unit 224.
Comprises a planetary gear P1, which is rotatably supported by a sun gear S1 connected to the motor shaft 202 and which meshes with the sun gear S1, and a ring gear R1 which meshes with the planetary gear P1, and the second planetary gear unit 224 comprises:
The sun gear S2 connected to the carrier C1, the planet gear P2 meshing with the sun gear S2, and the housing 21.
Ring gear R fixed to 4 and meshing with planetary gear P2
2, and the planetary gear P connected to the ring gear R1.
A carrier C2 that rotatably supports 2 is provided. Further, the differential device 206 is a double pinion type planetary gear device, and has a sun gear S3 connected to the constant velocity joint 210L and a ring gear R3 connected to the carrier C2.
Plural pairs of planet gears P3 that mesh with one and the other of the sun gear S3 and the ring gear R3, and mesh with each other.
a, P3b and a plurality of pairs of planetary gears P3a, P3b are rotatably supported and provided with a carrier C3 connected to the intermediate shaft 208.

FIG. 8 shows the speed reducer 204 and the differential device 20.
6 is a cross-sectional view showing a specific configuration of No. 6, and a speed reducer 20 for them.
4, each rotary element of the differential device 206 is a needle bearing, a thrust bearing, or the like.
It is positioned so as to be relatively rotatable and immovable in the axial direction with respect to the side housing 226, the intermediate housing 228, or other adjacent rotating elements constituting the fourteen. Lubricating oil is supplied to these bearings by a hydraulic pump 230 driven by a vehicle-mounted power source, and the lubricating oil is received by an oil pan 232 attached to a lower portion of the side housing 226. , And is pumped up by the hydraulic pump 230 and supplied again to the bearing portion. The side housing 226 includes
A pair of supply oil passages 234 and 236 for guiding the lubricating oil pumped from the hydraulic pump 230 are provided.
The lubricating oil that has been pumped to the No. 4 oil passage 238 provided in the intermediate housing 228 and the oil passage 24 provided in the carrier C1.
0, is guided to the oil passage 244 of the carrier pin 242 that rotatably supports the planet gear P1, flows out from the oil hole 246 provided in the radial direction, and lubricates between the carrier pin 242 and the planet gear P1. To do.

The lubricating oil pumped from the hydraulic pump 230 to the oil supply passage 236 receives the fitting shaft portion 248 of the constant velocity joint 210L.
The intermediate shaft 20 is guided to an oil passage 250 provided at the shaft center of the intermediate shaft 208 through a spline fitting portion between the L and the sun gear S3, and passes through a plurality of oil holes provided in the radial direction.
It is made to flow out from each part of 8 to the outer peripheral side. A part of the lubricating oil that has flown out passes through an oil passage 252 provided in the carrier C2, and the carrier pin 2 that rotatably supports the planetary gear P2.
Oil hole 2 provided in the radial direction of the oil passage 256 of 54.
58 and its carrier pin 254 and planetary gear P.
The parts of the speed reducer 204 and the differential device 206 are lubricated by, for example, lubricating between the two. The remaining lubricating oil flows into the gap between the intermediate shaft 208 and the motor shaft 202 and is supplied to the electric motor 200 side, flows out from the oil hole provided in the motor shaft 202 to the outer peripheral side, and the bearing 220L. And 220R, etc., and bearing 220R
The lubricating oil supplied up to is returned to the oil pan 232 through a return oil passage (not shown) provided in the housing 214.

[0006]

However, in such a power train for an electric vehicle, two lubricating oil passages are required to lubricate the planetary gears P1 and P2 of the speed reducer, and in particular, the planetary gear P2. Since the lubricating oil supply route to is complicated and used for lubricating other parts, it is difficult to obtain a sufficient lubricating action. In addition, the lubricating oil supplied to the bearing 220R along the intermediate shaft 208 is returned to the oil pan 232 through the return oil passage, but since the passage is long and the conduit resistance is large, ensure a sufficient flow rate. Is difficult. It is conceivable to adopt a high-output hydraulic pump to solve these problems, but in that case power consumption becomes large and it is not preferable for electric vehicles that want to extend the mileage per charge as much as possible. .

On the other hand, in order to lubricate the planetary gears P1 and P2, an oil passage must be provided in each of the pair of carriers C1 and C2.
Becomes larger and heavier, which is also a disadvantage in extending the mileage of an electric vehicle.

The present invention has been made in view of the above circumstances, and an object of the present invention is to enable a lubricating oil to be satisfactorily supplied to each part of a power train by using a small hydraulic pump with low power consumption. At the same time, it aims to reduce the weight of the power train.

[0009]

In order to achieve such an object, the present invention comprises an electric motor, a speed reducer, and a differential gear which are concentrically and serially arranged in a housing. A power train for an electric vehicle of a type in which one of two left and right powers that is output is transmitted to one drive wheel via an intermediate shaft through which the shaft center portions of the electric motor and the speed reducer are inserted, (A) The speed reducer includes a pair of planetary gear devices, and the planetary gears of the pair of planetary gear devices are integrally configured with each other.
While being rotatably supported by a common carrier pin, (b) a hydraulic pump driven by an on-vehicle power supply to pump lubricating oil, and (c) lubricating between the carrier pin and the planetary gear. Therefore, in order to lubricate each part of the power train including the first lubricating oil passage that guides the lubricating oil pumped from the hydraulic pump to the carrier pin thereof, and (d) the support bearing that supports the motor shaft of the electric motor, A second lubricating oil passage that guides the lubricating oil pumped from the pump from the speed reducer side to the electric motor side along the intermediate shaft and gradually flows out on the way, and (e) the speed reducer and the differential device. An oil pan provided at a lower portion for receiving lubricating oil that lubricates them, and (f) a second lubricating oil passage, and an oil pan in which a suction port of the hydraulic pump is arranged. In order to return the lubricating oil supplied to the supporting bearing on one of the drive wheels to the oil pan, it has a return oil passage formed in the housing and opening near the suction port of the oil pan. And

[0010]

In such a power train lubrication device for an electric vehicle, the planetary gears of the pair of planetary gear devices that constitute the speed reducer are integrally formed and rotatably supported by a common carrier pin. At the same time, since the lubricating oil pumped from the hydraulic pump into the first lubricating oil passage is guided to the carrier pin, the planetary gears can be satisfactorily lubricated even with a small-output hydraulic pump.
The other parts of the reducer, the differential device, the support bearings that support the motor shaft of the electric motor, and the like, are such that the lubricating oil pumped from the hydraulic pump into the second lubricating oil passage is electrically driven from the reducer side along the intermediate shaft. Lubricating oil, which is lubricated by gradually flowing out in the process of being guided to the motor side and is supplied to the support bearing on the one drive wheel side opposite to the reducer, passes through the return oil passage formed in the housing. The bread is returned. Since a sufficient flow rate of lubricating oil is supplied to the speed reducer and differential gears close to the hydraulic pump, good lubrication can be obtained, while the return oil passage is opened near the suction port of the hydraulic pump. The lubricating oil in the return oil passage is well sucked out by the hydraulic pump, and the lubricating oil is circulated at a sufficient flow rate even if the passage is long. Therefore, even a hydraulic pump with a small output can satisfactorily lubricate the support bearings and the like that are separated from the hydraulic pump.

On the other hand, the planetary gears of the pair of planetary gear units constituting the speed reducer as described above are integrally formed,
Since the planetary gears are rotatably supported by a common carrier pin and the planetary gear is lubricated only by the lubricating oil supplied from the first lubricating oil passage, the pair of carriers C1 and C2 are respectively lubricated as shown in FIG. Compared to the case where the oil passage is provided to supply the lubricating oil, the speed reducer is simply and compactly configured and the weight thereof is reduced.

[0012]

As described above, according to the lubrication device for a power train of an electric vehicle of the present invention, each part of the power train can be satisfactorily lubricated by using a hydraulic pump having a small output, and the weight of the speed reducer can be reduced. Therefore, the power consumption of the vehicle-mounted power source is reduced, which is extremely convenient for an electric vehicle in which it is desired to extend the mileage per charge.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view showing a power train 10 for an electric vehicle of this embodiment, and FIG. 2 is a skeleton view. In these drawings, the power output from the motor shaft 14 of the electric motor 12 is decelerated by the speed reducer 16 and then distributed to the left and right drive systems in the differential device 18. One power is transmitted through the cylindrical motor shaft 14 through the intermediate shaft 28 disposed concentrically with the motor shaft 14, the left first constant velocity joint 20L, the left axle 22L, and the left second constant velocity joint 24L. Left drive wheel 26L supported by a suspension device (not shown)
To the right side first constant velocity joint 20R,
It is adapted to be transmitted to the right drive wheel 26R supported by a suspension device (not shown) via the right axle 22R and the right second constant velocity joint 24R. The electric motor 12 and the speed reducer 1
6, the differential device 18 includes a cylindrical housing 30, a first side housing 32, a second side housing 33, a first intermediate housing 34, and a second intermediate housing 35.
They are concentrically and serially arranged in a housing formed of members.

The electric motor 12 is a permanent magnet type AC motor, an induction motor, a synchronous motor, a DC motor, etc., and has a cylindrical housing 30 and a first side housing 32 and a first intermediate housing fitted to both ends thereof. 34
It is integrally assembled in the space surrounded by. A stator 36 having a coil is fixed to the inner peripheral surface of the cylindrical housing 30, and the motor shaft 14 to which the rotor 40 is fixed has a pair of bearings 38L, 38.
It is rotatably supported by the first side housing 32 and the first intermediate housing 34 via R. The bearings 38L and 38R correspond to support bearings.

The speed reducer 16 and the differential gear 18 are arranged in a space surrounded by the second side housing 33 and the second intermediate housing 35. The speed reducer 16 includes a first planetary gear unit 42 and a second planetary gear unit 42, as apparent from FIG.
The first planetary gear set 42 comprises a planetary gear set 44,
A sun gear 42S connected to the shaft end of the motor shaft 14,
And a planetary gear 42P that is rotatably supported by the carrier 42C and meshes with the sun gear 42S.
The second planetary gear device 44 includes a planetary gear 44P integrally formed with the planetary gear 42P, and a ring gear 44R fixed to the second side housing 33 and meshing with the planetary gear 44P. Then, the rotation input from the electric motor 12 to the sun gear 42S is decelerated according to a predetermined reduction ratio, and is output from the carrier 42C to the differential device 18. In this case, the reduction ratio i (= rotational speed of the sun gear 42S / rotational speed of the carrier 42C) is equal to the first planetary gear unit 4
2, the gear ratio of the second planetary gear unit 44 (the number of teeth Z of the sun gear Z
_{When S} / the number of teeth Z _{R of the} ring gear is ρ ₁ and ρ ₂ , respectively, they are expressed by the following equation (1), and the gear ratios ρ ₁ and ρ ₂ are appropriately determined according to the desired reduction ratio i. Although the ring gear of the first planetary gear device 42 and the sun gear of the second planetary gear device 44 do not exist, the number of teeth Z _S of the sun gear and the number of teeth Z of the ring gear in the single pinion type planetary gear device are not present.
_{Since R} and the number of teeth Z _P of the planet gear have a relationship of Z _S + 2Z _P = Z _R , the gear ratios ρ ₁ and ρ ₂ can be obtained from this relationship.

[Equation 1] i = (1-ρ ₁ · ρ ₂ ) / {ρ ₁ · (1-ρ ₂ )} (1)

Further, the differential device 18 is a double pinion type planetary gear device, and includes the right side first constant velocity joint 20R.
A plurality of pairs of planet gears 46P ₁ and 46P ₂ , which mesh with one and the other of the sun gear 46S connected to the carrier 42C, the ring gear 46R connected to the carrier 42C, and one and the other of the sun gear 46S and the ring gear 46R, respectively, and a plurality of pairs of the planet gears 46P. ₁ , 46P ₂ are rotatably supported, and a carrier 46C connected to the intermediate shaft 28 is provided. As a result, the differential device 18 distributes the power input to the ring gear 46R and outputs the power to the carrier 46C operatively connected to the left drive wheel 26L and the sun gear 46S operatively connected to the right drive wheel 26R. To do.

In FIG. 1, the left side first constant velocity joint 20 is shown.
The L outer race 50L is non-rotatably connected to the intermediate shaft 28 via a connecting member 52, and the connecting member 52 is rotatably supported by the first side housing 32 via a bearing 54. Right first
The outer race 50R of the constant velocity joint 20R is spline-fitted to the sun gear 46S of the differential gear 18, and the second side housing 3 is interposed via a bearing 56.
It is rotatably supported by 3. Further, a sensor chamber 58 is formed between the first intermediate housing 34 and the second intermediate housing 35, and the motor shaft 1 is provided in the sensor chamber 58.
A rotor 60 that rotates integrally with the rotor 4 is provided, and an optical rotation speed sensor 62 that detects the rotation of the rotor 60 is attached to the upper outer peripheral wall of the first intermediate housing 34.

FIG. 3 is an enlarged cross-sectional view showing the vicinity of the speed reducer 16 and the differential gear 18, and the respective rotary elements of the speed reducer 16 and the differential gear 18 are formed by needle bearings and thrust bearings. The second side housing 3
It is positioned so as to be relatively rotatable and immovable in the axial direction with respect to 3, the second intermediate housing 35, or another rotating element adjacent thereto. Lubricating oil is supplied to the bearings by a hydraulic pump 64 (see FIG. 1) driven by a vehicle-mounted power source, and the lubricating oil is attached to the lower portion of the second side housing 33. The oil is received by the oil pan 66, and the hydraulic pump 64
It is pumped up by and is supplied to the bearing again. The suction port 68 of the hydraulic pump 64 is arranged inside the oil pan 66, and a strainer is attached to the suction port 68.

An oil passage 70 is provided in the second side housing 33, and an opening 72 into which lubricating oil is introduced from a hydraulic pump 64 is formed in an intermediate portion of the oil passage 70. The lubricating oil supplied into the oil passage 70 is separated into left and right parts and sent to each part. The lubricating oil that has proceeded to the left of the oil passage 70 is fixed to the carrier 42C via the oil passage 74 provided in the second intermediate housing 35, the annular groove 75 provided in the carrier 42C, and the oil passage 76. Guided to the oil passage 80 of the carrier pin 78, the carrier pin 7
8 through the oil holes 82 provided in the radial direction to lubricate the bearing portions of the integrally formed planetary gears 42P and 44P that are rotatably supported by the carrier pin 78.
The oil passages 70, 74, and 76 form a first lubricating oil passage, and most of the lubricating oil is a carrier except for a part flowing out from a fitting portion of the second intermediate housing 35 and the carrier 42C. It is supplied up to the pin 78.

On the other hand, the lubricating oil that has proceeded to the right of the oil passage 70 flows into the oil passage 84 provided in the second side housing 33, a part of which flows out from the oil hole 86, and the remaining portion. It is supplied to the fitting portion with the sun gear 46S. The lubricating oil flowing out from the oil hole 86 is received by the oil receiver 88 provided in the carrier 46C, and the carrier 46
The planet which flows into the oil passage 92 of the carrier pin 90 fixed to C, flows out from the oil hole provided in the radial direction of the carrier pin 90, and is rotatably supported by the carrier pin 90. Lubricate the sliding part of the gear 46P ₁ . Although not shown in FIG. 3, the planetary gear 46P
₂ is also lubricated in the same manner as the planet gear 46P ₁ . Most of the lubricating oil supplied to the fitting portion with the sun gear 46S passes through the annular groove 94 and the oil hole 96 provided in the sun gear 46S and the spline fitting between the shaft portion of the outer race 50R and the sun gear 46S. Although it flows into the part, a part of the second side housing 33 and the sun gear 46
It flows out from the fitting portion with S to the left and right, and lubricates the thrust bearing and the bearing 56 between the second side housing 33 and the sun gear 46S. A seal member is provided at a fitting portion between the second side housing 33 and the sun gear 46S so that a lubricating oil of a predetermined flow rate or more does not leak out. As shown in FIG. 1, the oil is returned from the oil hole 98 formed in the second side housing 33 to the oil pan 66. An oil seal 100 is provided between the second side housing 33 and the outer race 50R to prevent the lubricating oil from leaking to the outside.

The outer race 50R and the sun gear 46S.
Most of the lubricating oil that has flowed into the spline fitting portion of the is supplied to the oil passage 104 provided in the intermediate shaft 28, passing through between the lubricating oil and the stopper member 102 fixed to the sun gear 46S. , A portion of the intermediate shaft 28 and the stopper member 102 flow out from the fitting portion of the carrier 46C and the sun gear 46.
Lubricate the thrust bearing with S. The spline fitting portion is provided with a groove 105 at the bottom of the spline tooth and a notch is provided in the stopper member 102 so that the lubricating oil can circulate well.
In addition, a seal member is provided at a fitting portion between the intermediate shaft 28 and the stopper member 102 so that lubricating oil of a predetermined flow rate or more does not leak out.

The lubricating oil supplied into the oil passage 104 of the intermediate shaft 28 is made to flow out at a predetermined flow rate from a plurality of oil holes provided at intervals in the axial direction of the intermediate shaft 28,
While lubricating each part of the speed reducer 16 and the differential device 18,
Part of the gas flows to the electric motor 12 side through the gap 106 between the intermediate shaft 28 and the motor shaft 14. A part of the lubricating oil that has flowed to the electric motor 12 side through the gap 106 flows out from the oil hole 108 provided in the motor shaft 14 as shown in FIG. 1, and lubricates the bearing 38R. The lubricating oil that lubricated the bearing 38R flows down in the sensor chamber 58,
Second intermediate housing 35 and second side housing 3
3 from the oil passage 110 formed across the oil pan 66
While being returned to the first intermediate housing 34 and the motor shaft 1
4, an oil seal 112 is provided to prevent the lubricating oil from flowing into the electric motor 12. The oil hole 108 is formed between the oil seal 112 and the bearing 38R and satisfactorily lubricates the bearing 38R. Further, as shown in FIG. 4, breather holes 114 and 116 are provided in the upper portions of the second intermediate housing 35 and the second side housing 33, respectively, to prevent the lubricating oil from splashing to the outside. The inside of the chamber 58 is maintained at the atmospheric pressure to prevent the lubricating oil from seeping out from the fitting portion of the housing or the like due to the pressure difference. FIG. 4B
In the view of (a) viewed from the left side, the breather hole 116 is formed above the breather hole 114 and at a position slightly displaced in the circumferential direction.

The lubricating oil supplied to the left end portion of the intermediate shaft 28 through the gap 106 lubricates the bearing 118 provided between the connecting member 52 and the motor shaft 14 and the bearings 38L and 54. . Bearing 38L
Is satisfactorily lubricated by the lubricating oil flowing out from the oil hole 119 formed in the motor shaft 14. An oil seal 120 is provided between the first side housing 32 and the outer race 50L to prevent the lubricating oil from leaking to the outside, and between the first side housing 32 and the motor shaft 14. Is provided with an oil seal 122,
The lubricating oil is prevented from flowing into the electric motor 12. In this embodiment, the oil passages 70, 84 for guiding the lubricating oil pumped from the hydraulic pump 64 to the left end of the intermediate shaft 28,
The groove 105, the oil passage 104, and the gap 106 form a second lubricating oil passage. Then, the bearing 118 or 3
The lubricating oil that lubricates the 8L and 54 is the first side housing 32, the cylindrical housing 30, the first intermediate housing 3
4, and the oil passages 124, 126, 12 provided so as to extend over the second side housing 33 and communicate with each other.
8 and 130, the oil passage 130 is returned to the oil pan 66, and the oil passage 130 is opened near the suction port 68. These oil passages 124, 126, 128,
And 130 form a return oil passage.

The power train 1 configured as described above
Reference numeral 0 denotes a pair of planetary gear units 4 that constitute the speed reducer 16.
2, 44 planetary gears 42P, 44P are integrally formed and are rotatably supported by a common carrier pin 78, and the carrier pin 78 has an oil passage 74 from the hydraulic pump 64 via an oil passage 70. Since most of the lubricating oil supplied to the hydraulic pump is guided through the oil passage 76, a sufficient amount of lubricating oil can be used even when a low-output hydraulic pump with low power consumption is used as the hydraulic pump 64. Is supplied to the planetary gears 42P and 44P, which constantly rotate during traveling.
The bearing portion, specifically, the needle bearing 79 between the carrier pin 78 and the planetary gears 42P and 44P is satisfactorily lubricated.

The other parts of the speed reducer 16 and the differential device 18 are
The lubricating oil supplied from the hydraulic pump 64 to the oil passage 84 via the oil passage 70 is a spline fitting portion between the outer race 50R and the sun gear 46S, and the oil passage 10 formed in the intermediate shaft 28.
4. In the process of being guided to the left end portion of the intermediate shaft 28 through the gap 106 between the intermediate shaft 28 and the motor shaft 14, the oil hole 86
Although the speed reducer 16 and the differential gear 18 are close to the hydraulic pump 64, they are lubricated by being gradually discharged from the above, and therefore, a sufficient lubricating oil can provide a good lubricating action. The lubricating oil supplied to the left end of the intermediate shaft 28 is returned to the oil pan 66 through the return oil passages 124, 126, 128, 130, but the oil passage 130 is opened near the suction port 68 of the hydraulic pump 64. Therefore, the lubricating oil in the return oil passages 124, 126, 128, 130 is satisfactorily sucked out by the hydraulic pump 64, and the lubricating oil is circulated at a sufficient flow rate even if the passage is long. Therefore, even when a low-power hydraulic pump with low power consumption is used as the hydraulic pump 64, the bearings 38R, 38L, 54, 118 located at positions distant from the hydraulic pump 64 are used.
Can be satisfactorily lubricated.

On the other hand, the planetary gears 42P, 42P of the pair of planetary gear units 42, 44 constituting the speed reducer 16 as described above.
44P is integrally configured and is rotatably supported by a common carrier pin 78, and the planet gears 42P and 44P thereof are well lubricated by the lubricating oil supplied through the oil passages 74 and 76 of one system. Therefore, as shown in FIG.
As shown in FIG.
Compared with the case where 0, 252 is formed and lubricating oil is supplied, the speed reducer 16 is configured simply and compactly, and the weight thereof is reduced.

Thus, the power train 1 of this embodiment
According to the lubricating device No. 0, each part of the power train can be satisfactorily lubricated by using the hydraulic pump having a small output, and the weight of the speed reducer 16 is reduced. It is extremely convenient for electric vehicles in which it is desired to extend the mileage as much as possible.

Further, in this embodiment, since the sensor chamber 58 is provided separately from the accommodating portions of the speed reducer 16 and the differential gear 18, and the rotation speed sensor 62 is arranged in the sensor chamber 58, the rotation speed sensor is provided. The lubricating oil is less likely to be scattered or adhered to 62, and the rotation speed of the motor shaft 14 can be detected with high accuracy. The sensor chamber 58 has breather holes 114, 1
Since it is communicated with the atmosphere via 16, there is no fear that the lubricating oil will exude from the fitting portion of the housing or the like.

Although the oil seal 112 is arranged separately from the bearing 38R that rotatably supports the motor shaft 14 in the above-described embodiment, as shown in FIG. 38R and oil seal 11
It is also possible to employ the bearing unit 140 in which 2 and 1 are integrally assembled. An oil hole 142 is provided in the inner ring of the bearing unit 140, and an annular groove 144 is formed in the outer opening of the oil hole 108, so that the lubricating oil flowing out from the gap 106 to the oil hole 108 is annular groove. 144 through the oil hole 142 and the oil seal 112 and the bearing 38.
It flows into and out of R. FIG. 6 shows a case where the oil hole 108 is provided so as to communicate with the right side of the bearing unit 140, that is, the sensor chamber 58. In this case, the oil hole 142 is provided.
The annular groove 144 is unnecessary. The same applies to the bearing portion on the left side of the motor shaft 14, that is, the bearing 38L and the oil seal 122.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, the speed reducer 16 of the above-described embodiment is the first
Although the sun gear 42S of the planetary gear device 42 is connected to the motor shaft 14 and is configured to output from the carrier 42C, the applicant of the present application previously filed Japanese Patent Application No. 4-1575.
As described in No. 14, a sun gear that meshes with one of a pair of integrally formed planetary gears is fixed to a housing, and a carrier that rotatably supports the planetary gears is connected to a motor shaft, The sun gear that meshes with the other planetary gear is configured to output, or the sun gear that meshes with one of a pair of integrally formed planetary gears is fixed to the housing, and the ring gear that meshes with the other planetary gear is connected to the motor shaft. The configuration of the speed reducer may be appropriately changed, such as outputting from a sun gear that meshes with the other planetary gear.

Further, although the planetary gear type differential device 18 is used in the above-mentioned embodiment, a differential device using a plurality of bevel gears may be adopted.

Further, the lubricating oil passage of the above embodiment is merely an example, and can be appropriately changed according to the structure of the speed reducer or the differential device, the connecting structure of each part, and the like.

In the first lubricating oil passage of the above-described embodiment, the lubricating oil slightly flows out from the fitting portion between the second intermediate housing 35 and the carrier 42C, and almost all the lubricating oil reaches the carrier pin 78. Although it was supplied, a small oil hole may be provided in the second intermediate housing 35 so that a part of the sun gear 42S may be allowed to flow out in order to lubricate the bearing portion and the like of the sun gear 42S.

Although not illustrated one by one, the present invention can be carried out in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a cross-sectional view in which a power train for an electric vehicle equipped with a lubricating device according to an embodiment of the present invention is partially cut away.

FIG. 2 is a skeleton view of the power train shown in FIG.

FIG. 3 is an enlarged cross-sectional view showing the vicinity of the speed reducer and the differential gear of the power train shown in FIG.

FIG. 4 is a view for explaining a breather mechanism provided in the upper part of the sensor chamber in the embodiment of FIG. 1, (a) is a vertical sectional view,
(B) is the figure which looked at (a) from the left side.

5 is a cross-sectional view showing another aspect of the support bearing supporting the motor shaft in the embodiment of FIG. 1. FIG.

FIG. 6 is a cross-sectional view showing another lubrication mode of a support bearing supporting a motor shaft.

FIG. 7 is a skeleton view of a power train for an electric vehicle, which is a background art of the present invention.

8 is a cross-sectional view showing a specific configuration of a speed reducer and a differential gear of the power train shown in FIG.

[Explanation of symbols]

 10: Power train for electric vehicle 12: Electric motor 14: Motor shaft 16: Reduction gear 18: Differential device 28: Intermediate shaft 38L, 38R: Support bearing 42: First planetary gear device 44: Second planetary gear device 42P, 44P: Planetary gear 64: Hydraulic pump 66: Oil pan 68: Suction port 70, 74, 76: First lubricating oil passage 70, 84, 105, 104, 106: Second lubricating oil passage 78: Carrier pin 124, 126, 128, 130: Return oil passage

Claims (1)

[Claims] 1. An electric motor, a speed reducer, and a differential gear, which are concentrically and serially arranged in a housing,
One of the powers of the two left and right systems output from the differential device,
A power train for an electric vehicle of the type in which the shaft center portions of the electric motor and the speed reducer are transmitted to one drive wheel through an intermediate shaft that is inserted, wherein the speed reducer includes a pair of planetary gear devices. , The planetary gears of the pair of planetary gear devices are integrally formed with each other and are rotatably supported by a common carrier pin, while a hydraulic pump that is driven by an on-vehicle power supply to pump lubricating oil is provided. A first lubricating oil passage that guides the lubricating oil pumped from the hydraulic pump to the carrier pin to lubricate between the carrier pin and the planetary gear; and a support bearing that supports a motor shaft of the electric motor. When lubricating oil pumped from the hydraulic pump is guided from the speed reducer side to the electric motor side along the intermediate shaft in order to lubricate each part of the power train, A second lubricating oil passage that gradually flows out along the way, and an oil pan that is provided in the lower portion of the speed reducer and the differential gear, receives the lubricating oil that lubricates them, and has the suction port of the hydraulic pump arranged therein. And, in order to return the lubricating oil supplied to the supporting bearing on the one drive wheel side via the second lubricating oil passage to the oil pan, the oil is formed in the housing and near the suction port of the oil pan. A power train lubrication device for an electric vehicle, comprising: